Conduit bushing



Patented Sept. 9,' `1930 WELT-IAM J. EAHAN, 0F NEW HAVEN, CONNECTICUTCONDUIT BUSHING Application led March I23, 1927. Serial No. 177,795.

This invention relates to an improvement in that class of electricconduit-ttings com.- monly known as conduit-bushings.

VThe object of this invention is to produce a conduit-bushingconstructed with particular reference to providing simple and reliablemeans for locking it in place upon the oonv duit and, at the same time,providing a superior electrical ground-connection for the Sallie.

My invention further consists in a conduitbushing characterized by itsprovision with a threaded passage inclined inward toward the axisthereof and acombined lockinglandgrounding screw located in the saidassage and adapted to pass therethroug into oblique engagement with theperiphery of the conduit when the bushing is in place thereon. y

My invention further consists in a conduitbushing characterized as aboveand having certain details of construction and combinations of parts aswill be hereinafter described and particularly recited in the claims.

In the accompanying drawings:

Figa 1 is a top or plan view of a conduitbushing constructed inaccordance with my invention, with the combined locking-andgroundingscrew omitted;

- Fig. 2 is a view thereof in side elevation;

Fig. 3 is a detached view in side elevation o f the combinedlocking-and-grounding screw, together with its clamping-nut;

Fig. 4 1s a transverse sectional view of the 35 conduit-bushing asinstalled upon a conduit,

together with its locking-and-grounding screw and related parts; Fig. 5is a detached view in side elevation of another form which the combinedlocking- At0fand-grounding screw may assume; and

' Fig; 6 is a topor plan view thereof.

In carrying out my invention as' herein shown, the conduit-bushingproper comprises a .ring-portion 5 provided with .internal threads 6 forenga ement with the threads 7 at the outer end o a conduit 8 and with aninwardly-overhanging annular ange 9 adapted to seat against the outerend of the conduit, as shown in Fig. 4. This flange 9 is rounded incross-section, as shown, so as to provide a smooth and non-abradingterminal surface at the outer end of the conduit through which the wires(not shown) extend in the usual manner.

At equidistant points about its periphery, the ring 5 is provided withthree outwardlyextending tapered lugs 10, each of which is formed withal corresponding threaded passage 11 inclined inward toward the'axis ofthe bushing and adapted-to receive a combined locking-and-groundinlgscrew 12, which latter mounts a olampingnut 13, as shown in Figs. 3 and4.

In the use of my improved conduit-bushing,'it is screwed upon the outerend of a conduit, as shown in Fig. v4, so that one of its lugs 10 willpoint in thedesired direction, after which the perforation 14, at theflattened outer end 15 of a terminal 16 located at the outer end of aground-wire 17, is placed over the appropriate lug 10 in such positionthat itsperforation 14 is in line with the inclined threaded passage 11thereof. The screw12 is now passed through the perforation 14 of thesaid terminal and screwed into the passage 11 until its end is broughtto a firm oblique bearing against the peripher of, the conduit 8, withthe result that the con uitbushing is firmly secured against rotationwith respect thereto.

When the screw 12 has been firmly seated against the conduit asdescribed, the clamping-nut 13, which is carried by the screw, is turneddown until its under-face engages the outer face of the end 15 of theterminal 16, so as to bring the same into close electrical union withthe bushing, and hence with the conduit 8.

Other methods of installing my improved conduit-bushing upon a conduit,other than the method just above described, may, obviously, be'employed.

By my invention, therefore, the bushing is not only locked in place uponthe conduit, but a thorough electrical connection is prot5 vided betweenthe conduit and ground-wire l17, owing to the fact that the screw 12bites into the periphery of the former and provides a direct electricalpath from the same to the ground-wire 17 independent of the electricalico path through the bushing itself, which latter into close contactwith the threads thereof.

is not always dependable.

Instead of employing a clamping-nut such as 13 to connect theground-wire 17 to the conduit, I may employ the form oflockingand-grounding screw shown in Figs. 5 and 6. This screw 18 isformed with the usual polygonal head 19, which latter is provided withan axial socket 20 into which the end of the ground-wire 17 may besoldered in the usual manner.

l claim:

1. An article of manufacture comprising an annular member provided withan internally threaded conduit engaging opening, and provided further inthe annular portion with an additional internally threaded opening whoseaxis obliquely intersects the axis of the first named opening and liesin substantially the same plane andra threaded member in the saidperforation adapted to engage the periphery of the conduit to cant theinternal threads of the annular member into engagement with theconduit-threads.

i 2. As a new article of manufacture, a con-y duit-bushing consisting ofan internallythreaded annular ring adapted to` be screwed upon theexternally-threaded end of a conduit and formed with anobliquely-disposed inwardly-inclined threaded screw-receiving passageopening through its outer face;'and a combined locking-and-groundingscrew installed in the said passage and obliquely engageable with theperiphery of the said conduit so as to forcibly cant the said bushingwith respect to the conduit to jam its threads into close contact withthe threads thereof.

3. As a new article of manufacture, a conduit-bushing consisting of aninternallythreaded annular ring adapted to be screwed upon theeXteriorly-threaded end of a conduit and formed with anobliquely-disposed inwardly-inclined threaded screw-receiving' passageopening through its outer face; an inwardly-overhanging flange formedupon. the said ring and engageable with the outer end of a conduit; anda combined lockin and-grounding screw.installed in the said i passageand obliquely engageable with the periphery of the said conduit so as toforcibly cant the said bushing with respect to the conduit to jam itsthreads into close contact with the threads thereof. Y

4. As a new article of manufacture, a conduit-bushing consisting of aninternallythreaded annular ring adapted to be screwed upon theexternally-threaded end of a. conduit and having a portion of its outerface inclined and pierced by an inwardly-inclined threadedscrew-receiving passage; and a combined locking-and-groundin screwinstalled in the said passage and'ooliquely engageable with theperiphery of the said conduit so as to forcibly cant the said bushingwith respect to the conduit to jam its threads 5. As a new article ofmanufacture, a conduit-bushing consisting of an internallythreadedannular ring adaptedto be screwed upon the exteriorly-threaded end of aconduit; a lug projecting radially outward from the said ring and formedwith an inwardlyinclined threaded screw-receiving passage openingthrough its outer face; and a combined locking-and-grounding screwinstalled in the said passage and obliquely engageable with theperiphery of the said conduit so as to forciblyr cant the said bushingwith respect to the conduit to 'jam its threads into close contact withthe threads thereof.

6. As a new article of manufacture, a conduit-bushing consisting of an.internallythreaded annular ring adapted to be screwed upon theinteriorly-threaded end of a conduit; a l-ugprojecting radially outwardfrom the said ring and having an inclined outer face' pierced by aninwardly-inclined threaded screw-receiving passage; and a combinedlocking-and-grounding screw installed in the said passage and obliquelyengageable with the periphery of the said conduit sov as to forciblycant the said bushing with respect to the conduit to jam its threadsinto close contact with the threads thereof.

In testimony whereof, I have signed this specification. W. J. MAI-IAN.

